The aye-aye is a lemur, a strepsirrhine primate native to Madagascar that combines rodent-like teeth and a special thin middle finger to fill the same ecological niche as a woodpecker.

It is the world's largest nocturnal primate, and is characterized by its unusual method of finding food; it taps on trees to find grubs, then gnaws holes in the wood using its forward slanting incisors to create a small hole in which it inserts its narrow middle finger to pull the grubs out. This foraging method is called percussive foraging. The only other animal species known to find food in this way is the striped possom From an ecological point of view the aye-aye fills the niche of a woodpecker, as it is capable of penetrating wood to extract the invertebrates within.

The aye-aye commonly eats seeds, fruits, nectar and fungi, but also insect larvae classifying it as an omnivore. Aye-ayes tap on the trunks and branches of trees at a rate of up to eight times per second, and listen to the echo produced to find hollow chambers. Once a chamber is found, they chew a hole into the wood and get grubs out of that hole with their highly adapted narrow and bony middle fingers The aye-aye begins foraging between 30 minutes before and three hours after sunset. Up to 80% of the night is spent foraging in the canopy, separated by occasional rest periods. It climbs trees by making successive vertical leaps, much like a squirrel. Horizontal movement is more difficult, but the aye-aye rarely descends to jump to another tree, and can often travel up to 4 km (2.5 mi) a night.